The best nature writing from the newspaper, magazine, blog and book authors of the Lone Star State . . .

Thursday, October 23, 2008

Sandhill Cranes Are Returning to Their Wintering Groundsby Ro Wauer

October marks tat time of year when sandhill cranes are staring to move into their wintering grounds throughout South Texas. It is wonderful to have these large, graceful birds back in our fields and pastures. They will remain all winter, leaving for their northern nesting grounds in late April and early May. From now until May, one can find hundreds of these birds by driving the roads throughout the region.

Unlike the more famous whooping cranes that also winter in South Texas at Aransas National Wildlife Refuge and on adjacent coastal flats, sandhill cranes prefer old fields and pastures. Their needs are very different. While the whoopers overwinter only in wet coastal marshes, feeding on fish and other marine life, as well as marsh plants, acorns, and grains, sandhills prefer newly planted or harvested corn, sorghum, and grains. They may even range into semiarid areas west to the Big Bend country.

Our returning sandhill cranes often possess an odd color pattern, especially when they first arrive; their feathers are rust colored from the iron-rich feeding grounds where they spend their summer months. Normal sandhill crane plumage is overall gray with a whitish throat and cheeks, a bare reddish cap in adults, and dark legs, Whooping crane adults are all white except for a black facial pattern and reddish cap. In flight, whoopers display obvious black-and-white wings, while flying sandhills are all gray, except for their whitish throat. Both fly with their heads stretched for out and legs extended; great blue herons and egrets, also large birds that are sometimes confused with cranes, normally fly with their necks bent so that their head does not extend.

Sandhill cranes may be one of our most expressive birds. They often can be heard at a considerable distance, talking to one another in their unique call, a long, rolling, hollow rattle, like “garpoooooo.” Whether in flight or feeding in a field, they seem to spend a great deal of their time communicating.

Although huge flocks of 50 to 100 or more birds can be found regularly in South Texas, these groups can usually be broken into rather distinct family groups. Especially when they first arrive in our area, groupings of adults and juvenile are commonplace. The young generally remain with the adults all winter and gradually, by the time they are ready to head north again, mature to the point that they are difficult to distinguish from the adults.

Normally sandhill cranes mate for life, and as their mating season draws close, they often can be seen dancing before their mates. Although their mating displays in Texas are less elaborate than the dancing that occurs on their breeding grounds, it is till worthy of our observations. Courtship involved loud calling and marvelous dances with head bobbing, bowing and leaping, grass tossing, and running with wings extended.